Listening apparatus for telephones.



` w., W.l Gmes'y. A.

LISTENING APPARATUS POR TELEPHONES;

ARPLIO'ATION TILEIB 'JUNE 12.19%

f WJTNESSES.-

19.1111111121)JAN. 15, 1907.

W. W. GRIGSBY. LISTENNG APPPUTUS PUR TELEPHONES. APPLICATION FILED JUNE 12,1905.

vv a'sHBETs-SHEBT 2 WIM/55555. 1

No. 841,244. f PALTENTBD JAN; 15, 1907;

' A W. W. GNIGSBY LISTENING APPARATUS PON TELEPHONES.

. APPLICATION FILED JUNnlmigoa.'

3 SHEETS-SHEET 3.

A Imm/'E ys VUN rmi) y STATES PATENr oiiuon..

yf f.WiLLiAi/i W. tiincfsr-,` orffLAWHoN, LOUISIANA.

[LISTENING APPARATUS 'Fon TELEPHONES'.

vSpecification of Letters I atent. pplication filed June12,1906. Serial No. 321.396..

Patented Jan.15, 1.907.'4

ToiiaZZ jwlwm 'it '7n/tty concern:

' f "Be-it known that I, WILLIAM W. GRIGSBY,

a -citi'z'enbf` the United States,v residing at L awlijoii, in thegparish of Bienville and State ofLouisiania, havjefinvented a new and useful Listening Apparatus for Telephones, of

` Awhich the following is a specification.

' The y,principal object ot the present invention is to provide 'an apparatus whereby the superintendent or chiei operatorotl a telephone-exchange may overhear conversations carried 'on between the switchboard operat-or' and the different subscribers. Y

A further object 'of the invention is to lconstruct an apparatus of this type by which the connect-ions may be made Without the knowledge of the switchboard operator.

With these and other objects in view, as

will morefulljT hereinafter appear, the inven-y tion consistsin certain novel features of construction. and arrangement Vof parts herein'aftei. fully described, illustrated in the accompanying drawings, and particu'larlu'wT vvpointed out in the appended "claims, it being understood that various changes in the form,

'-proportions, size, and minor details of the 'structure may be made Without departing from the -spirit or saeriicingany of the advantagesof the invention.

In the' accompan'j ig drawings, Figure 1 is a general diagram' vot a listening apparatus arrangedfand constructed in accordance With the invention. Fig. 2 is a planvieu' of the mechanism `employed by the chief operator for determining the telephone-line with which he is in communication. Fig. 3 is. a'n inverted plan view of the same. Fig, 4 is a transversesectional vieu"- ofthe mechanism yon theline 4 4 of Fig. 2. Fig.' 5 is a plan View of the Vcircuit-'elosing devices employed adjacent to the telephone switchboard for g connecting to the various lines.' Fig. isan jinvertedplan view of the same. Fig. ,7 is a cross-section of 7v 7 of F1g.-'5.

*ployed tof 'indicate ycorresponding parts throughout the several figures ofthe: drawings f placed at some pointadjacent to the switchboa d., and the apparatusB .may be placedatv 'any desired distance'A therefrom, preter'abljT the mechanism 4on the' line Similar characters of reference are emcarrying 4out `the invention an 'ratus (desig'zna'tedI generalljT A 1n Fig. 1)l is in theoflice of thechieffoperatOr, and thetf energize' latter by'listening at a telephone' @may overhearjthe conversation on any-line with which he chooses to be placed in communication, The mechanisniwvhich is placed adjacent to the switchboard comprises a suit able basedisposed shaft v11, having -upper and lowerbearings 12, that are carried by suitable brackets or bridge members 15f .This shaft carries an arm 16, that is forinedof insulating material, and is provided .with VtWocontacts 17and18, preferably in the nature'of springbrushes. The' shaft carries or is formed of separate metallic sleeves 1 9 and 20,' that yare; insulated from each other, and these are en -v gaged, respectively, by brushes' '21. and-:122, The sleeves are electrically'connected tothe travelin contacts 17 and 18, and=.thu's 'a're in electrica connection With the brushes 21jvv and 22, respectively. f Thesebrushesare carried by studs or binding-posts 2 4 `and 25, from,

which lead currentfconducting. fwiresf 26 and 27. Secured to the shaft-is a crown-ratchet 30," the teeth offwhich' arearranged` to .be/eri'- gage'd by afpaWl-Slg carried by lan armature 32, that is ddisposed Within the field-'of yforce of each in circular series. concentric4 With'each other and with the' oftheshafr'ft"-11.` `The .contacts are in radially-arranged'- pairs- ,that

are Aconnected'in 'circuit by the :contacts 17 f andI-S, Leading i"i'jom each pairfof contacts are ivi-res 4 0 Vand 41, that are connectedto the opposite ends of the seconda'rv-of-aninducto- -1 oc 'riurn being in series with one of the line-Wires. In

the 'diagram live line-Wires a b @die are shown,

v and i each includes primary ofthegiiiduction-coil, and adjacent-5 t0-ea'c-h vprimary-'is a 105 secondarycoilthat-is connected to tw'oof the .contacts 3 6.

- through the electromagnet the latter \vill"be d and A thelpfa'vvl 1 ll; 'advance' the 1- 1o plat/e 10, through which extends a verticallyratchet .to thev extentfoi a single: tooth,- .so-

tliatthe contacts 1 7. andf 18 Will be moved'v 'romfcigage'm'ent with one pair of contacts 3'6 1'nto engagement'wth'another pair of con- 'r "la'tter"beingfbesti;shown in Figs. 21, 3, and 4.

' 'apparatus includes a b'ase- The mdicat' l plate l45,'ha anopenn'g for the passage of .-PQSed magnet "53,1'and each time theelectromagnet the crownratchetwill be ad.

a shaft 46, hataismounted in bearings. 47 fcarried by bridges or brackets y48, secured to the base. '.Sgecured'to the shaft isqacrow'n# f 'ratchet "50', which is' engagedby a lp'a'vvl 51, carried by'V an armature-lever 5 2, that is'fdiswithin "the 4fieldl of forcel of 'an electro- 'fis'y energized ratchetis held 'from movementin the reverse direction by-galockpawl 54;4 To the up er -port-ionof the sha-ft' is secured a revolu le :pointer'55 that is arranged to move over a circular'. {56, bearinglnumerals of a number v4co1''respondingto the number of 'pairs of contacts" 36- 1 carried by lthe member' A,' and the 3 5,4 series, "so th" tja circuit closedtor can," therefore, 'instantly determine.- the linevzith which the,Contacts-1'7fand 18 are in -.com munication.- i 1 i Tracing novvthe circuit from'the electromagnet 33,'itf'will1be seen that wire^26 is con-l nected toijthe electromagnet 53, and this through Wire "5' 7 to the' rimary 58 of an induction-coil, thence leading `to "a 1battery 5 9,

jaj: circuit -c'loser 60, and from the latter ythrough the-Wire 61 to the electromagnet 33. The switcher-key may be' in the form of altelegraph-key and may be depressed by thel "chiefopera'tor'for -thepur ose yof closing an energized circuit through' t e electromagnets ligand-53. This Will result in advancing the r'contacts1,17 a1 1cl 184mb' engagement withl the su(icessive pairst of lcontacts 36, and thel sec-V v-o'ndaries 43"'-ofgth`e diiferentlines `Will therefV fore vbe"successively connected with the tele- 'phone C-off the chief operator, Who by'li'sterh` 'ing "may -determine v'the .manner'in which the .switchboardperator is 'attendingto busix60.

vfIclaim- 1 ,l

1'1.4 'Inlli'stening apparatus' for telephone'ex changes, aimovableLcontactf carrier,v contactsy arranged to be successively fengagedthereby and connected in circuits'tliat are inductively DESS..-

thrug'hjoe will .be clcsedathrough -both 1,and they will: be.v Simultaneously'cperated. The chief opera-' 'arranged'to enga 'step-by-step ratc related to the t'elephonelinemeans for imparting a step-by-step movement to the-mov-y ,able-contact'carrier, and a telephone-receiver electrically connected V to themovable contacts..

4 2. In listening apparatus fortelephone systems, an annular'series of stationary con'- t'acts connected in circuits that are inductively related to the telephone-line, a revolu" ble contact-carrying arm, movable contacts means *for operating the revoluble' contact'- carrier.

3. lIn -listening apparatus for telephone.

systems, an annular series of stationary con'- contact-c'arryin'g arm, means for revolving .the same, contacts supported -by said arm and arranged lto engage the successive' sta-' tionary' contacts, 'and' a 'tele hone-receiver arrangedni-n acircuit of Whic contacts ferm the terminals. 1

4. -In listening apparatus for telephone systems, -an 'annular seriesof statio'narycontacts, .said contacts being arranged in circuits ythat are in communication With the diiferent telephone-lines,a shaft, collecting, rings or sleeves: on said shaft, vbrushes engaging said the lmovable arranged on the arm and'adapted to engage, the stationary contacts, a telephonereceiver connected to the movable. contacts,A and' tac'ts arranged in circuits that are' inductively related to' the stationary lines, afrevoluble rings or sleeves, a stationary receiver con-` nected in a circuit that extends betweensaid brushes,fan.arm carried by the shaft, con- `tac'ts supported'by said arm and arrangedto .engage the stationary contacts, a ratchet on L the shaft, -a-nd -an electromagneticallyeactue ated 'paWla for imparting .a step-by-step movement to said ratchet.

5; In listenin apparatus-'fon tele lione systems, 'a base-p ate, contacts carried y the.

base-plate andv arrangedin continuous annular series, all of said contacts being insulated'y from each other, current-conductors leading from. thecontacts and inicommu'nication With thediferent tele hone-lines, a shaft arranged at the center 'or theseries4 of contacts, an arm carriedvby said shaft, movable con-- tacts carried' by the arm and .arranged-,to

4engage the stationary contacts, -collectir'ng- -sleeves on the shaft, said'sleevesl being conlIO nected tothe movable contacts, brushes'en-A gaging said sleeves, a telephonerecelver' 1n a circuit of which the'sleeves form terminals, aratchet secured to thesh'aft, a 'paWl- 'engagiz'iglsaid ratchet, an electromagnet foractuatingf the paWl, saidmag'net being arranged inthe.

circuit of 'thereceiver., n

lar series of contacts j .carried 'byfone jof; said, l bascpla'tes, and viriductirely rela-ted '-.tcthe gie th' Stationary eont'acts', af et mechanism' for"advanc-' 1 different j telephonelines, fmovablecontacts uriu'm, and a telephonedeceiver connected to ing the movable contacts and including an y the secondary ofthe induetorium. v

electromagnet, an indicating dial on the 'other bese-plate, a shaftat'the center of the dial, a Pointer onSaid shaft, ve, Step-by-step 5 mechanism for turning the shaft, saidm'ech-- anism including an. electromagnet, a.- circuit extending fromthe movable contacts chron l1 both .of the electromaguetsJ said `circu1 cludng also a keyor switch, a source of'ele 1o trieal energy and the primary of an indctoln .testimony'that I claim the foregoing' as my own VI have hereto vaflixed mysignat-ure 

